Nanovaccine helped mice overcome type 1 diabetes

CHICAGO (Reuters) - An experimental vaccine containing tiny molecules of an immune-system protein was able to reverse type 1 diabetes in mice, raising hope that it might work in people, Canadian researchers said on Thursday.

But not all T cells cause harm, said Dr. Pere Santamaria of the University of Calgary in Alberta, whose study appears in the journal Immunity.

"Essentially, there is an internal tug-of-war between aggressive T cells that want to cause the disease and weaker T cells that want to stop it from occurring," Santamaria said in a statement.

Santamaria's team wanted to find a way to counteract the harmful autoimmune response without compromising general immunity.

They developed a so-called nanovaccine -- particles many times smaller than a cell and coated with protein fragments specific to type 1 diabetes. These were bound to molecules that play a critical role in presenting these protein fragments to T cells.

When the team gave the vaccine to mice with an early form of type 1 diabetes, they found the vaccine slowed the progression of the disease. And in mice that had full-blown diabetes, the vaccine helped restore normal blood sugar levels.

The team said the vaccine appears to work by expanding the number of T cells working to fight off the attack of aggressive T cells that destroy the insulin-producing beta cells.

And they said the findings may lend clues about how to reverse other autoimmune diseases, such as multiple sclerosis or rheumatoid arthritis.

Teodora Staeva of the Juvenile Diabetes Research Foundation said in a statement the study was promising because the treatment worked only on the immune cells specifically focused on aggressively destroying beta cells, without compromising the rest of the immune system.

Type 1, formerly called juvenile diabetes, represents about 10 percent of the estimated 180 million cases of diabetes globally. Most diabetics have type 2, the kind linked with a rich diet and lack of exercise.